New interstellar object 3I/ATLAS: What we know about this rare cosmic visitor

The new interstellar object 3I/ATLAS is creating quite the buzz. Here's everything we know so far about this cosmic interloper.

Astronomers have confirmed a rare and extraordinary discovery: the third known interstellar object to enter our solar system. Named 3I/ATLAS, where 3I stands for 'third interstellar', and designated C/2025 N1 (ATLAS), the object was first spotted on July 1, 2025, by the Deep Random Survey remote telescope in Chile, part of the ATLAS (Asteroid Terrestrial-impact Last Alert System) project.

It's a significant find. But what exactly is it? Initially referred to by the temporary designation A11pl3Z, 3I/ATLAS drew immediate attention from astronomers because of its peculiar motion. Rapid follow-up observations and reanalysis of previous data led to the preliminary conclusion that the object was not bound by the sun's gravity. That makes it an interstellar object — only the third ever seen after 1I'Oumuamua in 2017 and 2I/Borisov in 2019. 'If confirmed, it will be the third known interstellar object from outside our solar system that we have discovered, providing more evidence that such interstellar wanderers are relatively common in our galaxy,' Mark Norris, Senior Lecturer in Astronomy at the University of Central Lancashire, told Space.com at the time of 3I/ATLAS’s discovery.

Even more exciting? 3I/ATLAS is the largest and brightest interstellar object yet, which means it could help scientists unlock clues about the formation of other star systems.

How do we know it's interstellar? Could it strike Earth? Can we send a spacecraft to intercept it? Here are all of your questions answered and everything else you need to know about this rare discovery, including why it may be the first of many more interstellar objects to be detected.

How do we know 3I/ATLAS is from another star system?

What is 3I/ATLAS?

Could 3I/ATLAS strike Earth?

Is 3I/ATLAS visible in the night sky?

When will professional telescopes observe 3I/ATLAS?

Why is 3I/ATLAS so interesting to astronomers?

Can we send a spacecraft to intercept or fly by 3I/ATLAS?

Why are astronomers suddenly finding interstellar objects?

According to the source: Space.